BMW 6 Series 640d M Sport Review

 

BMW 6 Series 640d M Sport

Test date 27 October 2011  Price as tested £66,745


Having launched the cloth-top version in the UK in March, BMW is now introducing the new BMW 6-series coupé. The closed-roofed two-door is billed as the firm’s ultimate grand tourer: a car with comfort, luxury, spaciousness, efficiency and high-end technology that’s unrivalled in its class.

But if this version of the 6-series really does prove to be a car of significantly greater substance than the last, it will probably be in no small part thanks to its engine, and the arrival of this 640d gives us our first chance to put BMW’s very latest 3.0-litre twin-turbocharged diesel under our road test microscope. Considering this car maker’s incredible track record in producing benchmark diesel motors, equally miraculous performance and efficiency are definitely on the menu.

Trademark BMW handling is perhaps what’s most in question. The more powerful 650i convertible tested earlier this year oozed competence but lacked precision, involvement and driver reward. So it’s for the 640d to show that M Sport spec and a fixed roof can sharpen the 6-series’ character.

Design 

BMW aimed for a more elegant, athletic look with the third-generation 6-series, with some success. The long bonnet profile, wide-hipped stance and taut surfaces of the new car make it more appealing, to these eyes, than the rather amorphous car it replaces.Sizable proportions help. At almost 4.9m long, it has grown 74mm.
The car’s underbody construction is a unitary body in white made of steels of various strengths, with aluminium used for the front suspension turrets. On top of that, the 6-series has a more innovative outer skin designed to boost rigidity and save weight. Aluminium doors and bonnet border plastic front wings, while the bootlid is made of a glassfibre-reinforced plastic composite. Despite the variety of materials used, the car’s paint finish is uniformly good and its panel fit consistent.

Like the 7-series and 5-series saloons, the 6-series is suspended via double wishbones at the front and BMW’s multi-link-style ‘integral’ rear axle. As standard fit, all versions have fixed-rate dampers, conventional anti-roll bars and electro-mechanical power steering with Servotronic speed-dependent assistance.

Adaptive dampers and anti-roll bars come as part of BMW’s Adaptive Drive options package. Our test car had them, adding reach to the car’s Performance Dynamic Control selector – which, in the 6-series, has a new Comfort+ setting to match Comfort, Sport, Sport+ and Eco Pro.

The car’s 309bhp six-cylinder twin-turbocharged diesel engine is probably the technical high point (see Under the skin, p67). But amid options such as surround-view cameras, a night vision system, a head-up display and what’s described as the most advanced hi-fi audio system yet offered on a BMW are adaptive LED headlights with a cornering function. They light the road to the left and right of the dead-ahead dependent not only on speed and steering angle but also vehicle yaw rate. Trust Munich to come up with headlights capable of compensating for unexpected night-time oversteer.

On The Road

 

We wondered if the 640d would achieve both 150mph and 50mpg in our hands. In the end, it didn’t manage to quite hit those figures on the one-mile straight at MIRA’s proving ground or over our touring route. But a wind-assisted one direction maximum of 146mph at MIRA and 46.4mpg on a simulated motorway run are far from shabby for an 1840kg coupé.

When you start the six-pot diesel, it settles into a hushed, thrummy idle; rumbly but not clattery. Reach for a gear and you’ll find an electronic selector of the kind that we’ve become so familiar with that anything retaining a mechanical operation now feels old-fashioned. A mechanical connection would, however, remove the irritation that the lever will move yet not select a gear if you’ve not pushed the release button on its side far enough. It’s not a big deal, but we suspect neither would a fix be. Likewise, we’d prefer more confirmation that the ’box has dropped into park than just a light on the dash.

Watch our BMW 640d M Sport video review 90sec verdict
Still, the eight-speed gearbox itself is a unit that displays its competence and intelligence by shifting so smoothly and cleanly that, for the most part, it barely enters your consciousness that it’s doing it at all.
What does make its presence felt is the amount of performance on offer. From a standing start, the 640d is quite capable of overpowering its rear tyres and setting its ESP light ablaze as it heads to 60mph in only 5.3sec, and 100mph in just 13.1sec. If you’re at 30mph and ask for full throttle, just 4.5sec later you’ll hit 70mph. This is a car in which you’ll never want for performance, and it’s all delivered with a sound that’s the best automotive diesel noise this side of a Challenger II tank: extraordinarily smooth and powerful sounding, with no unwanted top-end overtones.

That the 640d can do all this while returning 46mpg at a cruise and comfortably 32mpg at any time makes this one of the finest powertrains available today.

It doesn’t take long in the 640d to realise that you’re at the wheel of a big car. It’s long but also wide, which makes threading it along tight streets no easier than it would be in one of the four-doors on which the 6-series is based. That should be no great surprise, but it is a shame this coupé doesn’t come with a greater feeling of natural agility and nimbleness of the sort that marks out, say, a Porsche 911.

Instead, think of the 6-series as a more natural rival, in size and demeanour if not in price, to a Mercedes CL; a long-legged, easy-going luxury cruiser rather than a sports coupé. Between the Porsche and Mercedes-Benz, you’d find a Jaguar XK doing half the job of each. Question is, where does the BMW fit?
Closer to the Mercedes is the short answer. The longer answer requires an explanation beginning with the fact that, like so many high-end BMWs, the 640d rides on run-flat Michelin tyres and so seemingly demands adaptive damping dexterity before it’ll do the kind of work BMW wants it to.

The damping set-up can be moved from Comfort+ through a range of increasingly firm settings to Sport+, each bringing more body control at a loss of ride quality. On most motorway journeys, we left it in Comfort and found few places where the surface was so smooth that Sport or Sport+ provided an acceptable level of ride quality. If you do accept the harshness, you’ll find a level of natural balance and ability that does the BMW credit.

In any mode, the blend of ride and handling is seldom poor, just less optimised than we’d like given this car’s price – it lends the 640d a forever gently unsettling feeling that it’s not quite as good as it could be. What the 640d does always offer, mind, is an excellent level of cabin quietness and refinement. Few cars at this or any price feel quite so sophisticated and isolated from noise. The 6-series gets that bit of the grand touring regime spot on.

Living

Although its wheelbase has grown by 75mm, it still isn’t quite a proper four-seater. By class standards, the cabin is quite generous; luxurious up front, with more accommodating rear seats than you’ll find in anything short of a Mercedes-Benz CL. There’s enough rear headroom and legroom for small adults, but six-foot occupants still haven’t a hope of sitting line astern. In a 4.9m car, you’ve a right to better. But you couldn’t ask for a bigger boot: its 460 litres is within a couple of shopping bags of the big Merc’s, and 25 per cent more than a Jag XK’s.

Our test car came fitted with the sports seats, textured aluminium inlays and sports steering wheel that M Sport specification buys, but even without those augmentations, this would be a superbly agreeable place to spend time. There’s a fine driving position with plenty of adjustment, a set of clear instruments and an impressive mix of cabin materials, ranging from leather, through matt-finish aluminium, to solid tactile plastic. A fixed, 10.2in colour display screen dominates the whole fascia.

For UK buyers, that screen is part of the standard equipment roster, as is Dakota leather, electric memory heated front seats, an eight-speed auto, cruise control, automatic lights and wipers, and BMW Professional sat-nav with multimedia functionality.

But for all the comfort and apparent quality, you do expect a little more richness and piquancy from the cabin of a £60,000 car. Considering it’s priced so closely to Maseratis and Aston Martins, the 6-series’ cabin has a strangely cold, business-like ambience. It doesn’t really create a sense of occasion for the driver.
Provided you need to make no more than occasional use of those rear seats, the 640d has this section all sewn up. It’s cheaper than an XK Portfolio to buy and will retain 10 per cent more of its value over three years.

The deciding factor for many will be the 640d’s economy. It returned 45.5mpg on our touring economy test and is at least 50 per cent more economical than the next most frugal car in a class where petrol is still totally dominant.

Managing not to get seduced by the car’s long and expensive options list is the one caveat we’d advise. A fully loaded 640d M Sport will set you back £98,000, and it would be very easy to spend £85k on the car and still leave out the options that’ll add the most value at resale time.

 

Verdict

The BMW 6-series 640d is an easy car to admire. Few and far between are the coupés that can reach the other side of 140mph in less than a mile from a standing start, and fewer still have an engine that can also approach 50mpg on a gentle cruise.

But it’s the engine and transmission that play the starring roles in the 640d’s dynamic production. They have the diversity and the ability while the rest of the dynamic cast play a supporting role with competence, but not sparkle. The 640d is a supremely quiet cruiser but it only matches that with a truly compliant ride in its softest suspension modes, where it wants for tighter body control. Its cabin, too, is as clean and functional as you could hope for, but it is too short of ambience for a car with a price that starts with a six. Ultimately, the 640d is an easy car to like and live with, but a hard one to fall for.